The present invention relates to an assembly type stator structure having flat wire wound coils, whereby coils, wire groove seats, stator rings, and stator teeth of an electromotor or generator can be separated from the stator.
An electromotor or generator must operate at an optimal working point to have the highest operational efficiency. Therefore, it is necessary to accurately control the operational range. From the equation: E=xcexa9xc2x7Dxc2x7Bxc2x7Lxc2x7N/2=xcexa9xc2x7KE, wherein E is the power source voltage, xcexa9 is the armature""s rotation speed, D is the armature""s outer diameter, B is the magnetic flux density of air gap, L is the stacked thickness, N is the total number of turns of conductors, and KE is the counter electro force coefficient, we know that the counter electro force coefficient KE is inversely proportional to the armature""s rotation speed xcexa9, and KE also relates the armature""s outer diameter D, the magnetic flux density of air gap B, the staked thickness L, and the total number of turns of conductors N. If the armature""s outer diameter D, the magnetic flux density of air gap B, and the stacked thickness L are fixed, changing the total number of turns of conductors N will change the rated highest rotation speed. However, as shown in FIGS. 3A to 3G, although coils differ due to different sizes of wire material, only 6 turns of coils can be wound in FIGS. 3A, 3B, and 3C, 8 turns of coils can be wound in FIG. 3D, 10 turns of coils can be wound in FIG. 3E, 12 turns of coils can be wound in FIG. 3F, and 14 turns of coils can be wound in FIG. 3G. Evidently, if it is necessary to wind 7, 9, 11, or 13 turns of coils due to the requirement of the working point, the above figures cannot be chosen and the number of turns of coils in the above figures needs to be discounted, hence reducing the occupation ratio of coils in wire groove seats. Moreover, because there are inevitably gaps existing between circular wire materials, the occupation ratio of coils cannot be highly utilized, hence reducing the cross-sectional area of coils and increasing the impedance of copper wire of coils. From the equation: P=I2xc2x7R, wherein P is the power loss of copper wire of coils, I is the current of coils, and R is the impedance of copper wire of coils, the power loss of copper wire of coils is also increased.
U.S. Pat. No. 5,866,965 discloses a variable reluctance motor having flat wire wound coils, wherein flat wire wound coils 15 are provided. The flat wire wound coils 15 are wound using a cylinder winder and slipped onto stator poles 13. The flat has two corresponding faces, two corresponding sides, and a start winding 15b and a finish winding 15a. The faces are slipped onto the surface of the stator pole 13. One of the two sides is disposed on the flat 13a. The start winding 15b is thus hidden inside a coil formed by winding the flat wire, as shown in FIG. 2 of U.S. Pat. No. 5,866,965. Therefore, it is necessary to perform two times of processing to lead out the start winding 15b, as shown in FIG. 1 of U.S. Pat. No. 5,866,965. The start winding 15b of the flat wire wound coil 15 must be folded and turned three times to be led out. The procedures for leading out the start and finish windings 15b and 15a are shown in FIGS. 1A to 1G of the present invention. Therefore, the processing is difficult, and the cost is high. FIG. 1H of the present invention can be compared with the coil 15 shown in FIG. 1 of U.S. Pat. No. 5,866,965.
Besides, if the motor disclosed in U.S. Pat. No. 5,866,965 is to be applied in occasions of high current, the coil must have a large cross-sectional area. In other words, it is necessary to use thicker flat wire, resulting in difficult processing in folding and turning the start and finish windings three times. Therefore, the disclosure of U.S. Pat. No. 5,866,965 is not suitable to the occasions of high current.
Furthermore, the width of the faces of the flat wire must be slightly smaller than the width of the stator pole 13. Otherwise, the start winding 15b cannot be folded and turned three times and then led out (please refer to FIGS. 1A and 1B of the present invention).
The coil 15 of U.S. Pat. No. 5,866,965 applies to the situation that the thickness of the stator pole 13 of a stator 11 of a variable reluctance motor is larger than the depth thereof, as shown in FIG. 4 of U.S. Pat. No. 5,866,965. Therefore, the coil 15 can still have a reasonable occupation ratio in wire groove. However, if the manufacturing way of coil in U.S. Pat. No. 5,866,965 is applied to stators of the present invention, the occupation ratio will decrease and the flat wire wound coil will become thinner. The coil 15 of FIG. 1G is slipped onto a longitudinal vertical pole end 211 of a wire groove seat 21 in FIG. 2. Because the depth 218 of the vertical pole end 211 is larger than the width 217 thereof, and the width of face of the coil 15 cannot be larger than the width 217 of the vertical pole end 211 (otherwise the start winding 15b cannot be folded and then led out), the occupation ratio of the coil 15 of U.S. Pat. No. 5,866,965 will be much lower than that of the coil 31 in FIG. 4C of the present invention. Simultaneously, the thickness of the side 15d of U.S. Pat. No. 5,866,965 will also be much lower than that of the side 315 in FIG. 4 of the present invention.
The above reduction of occupation ratio of coil will lead to increase of impedance of copper wire. The power loss of copper wire of coil thus also increases to cause a high working temperature of copper wire. Because the impedance of copper wire is proportional to the working temperature of copper wire, the impedance of copper wire will increase proportionally. Therefore, how to increase the occupation ratio of coil in the wire groove to reduce the impedance of copper wire is a very important issue in manufacturing a high-efficiency electromotor or generator.
For stators of a conventional electromotor or generator, because a high-current working environment is required, thicker circular coils are used in wire groove seats and are wound and arranged in successive layers, as shown in FIGS. 3A to 3H. Even a whole array of wires are adopted, the occupation ratios of various kinds of circular wires in the same wire groove seat will differ due to different sizes of circular wires. Simultaneously, various kinds of numbers of turns of coils cannot be arranged using different circular wires in the same wire groove seat with uniform occupation ratio, as shown in FIGS. 3A to 3G. Much trouble will arise in the design of rotation speed in the working range of an electromotor or a generator due to the above reasons. From the equation: E=xcexa9xc2x7Dxc2x7Bxc2x7Lxc2x7N/2=xcexa9xc2x7KE, we know that the counter electro force coefficient KE is inversely proportional to the armature""s rotation speed xcexa9, and KE is proportional to the armature""s outer diameter D, the magnetic flux density of air gap B, the staked thickness L, and the total number of turns of conductors N. Therefore, when electromotors or generators of the same volume are designed to be used in different working ranges, change of the total number of turns of conductors N will change the counter electro force coefficient KE.
Based on the above reason, the object of the present invention is to propose an assembly type stator structure having flat wire wound coils, wherein the thickness of flat wire is changed. Because the total thickness of coil end divided by the required number of turns of a flat wire wound coil 31 equals to the thickness of a side 315 of the flat wire wound coil 31 (as shown in FIGS. 4A to 4C), coils of various kinds of numbers of turns can be flexibly designed, and the counter electro force coefficient KE can be exactly controlled. Moreover, because there is no waste of arrangement gap of wire material, the occupation ratio in wire groove is inevitably higher.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing, in which: